Hydroponics is a century old system for growing plants without the use of soil, by immersing their roots in a nutrient-rich solution instead. Aside from not requiring soil, hydroponics also enables the recirculation of water through the system, drastically cutting the volume of water necessary for growth.
Hydroponic systems fall into two major types: those in which the plant roots are suspended in only the mineral solution (solution culture) and those in which the plant roots are immersed in another solid medium, like gravel or clay pebbles (medium culture).
The techniques for executing hydroponics range from the very simple to the considerably complex. The simplest technique, hand watering, involves suspending the plant roots in water or a substrate and adding water to the system often enough to keep the roots submerged at all times.
Plants need to have fresh nutrients available for healthy growth. Ensuring regular reservoir changes every week is essential. pH and electro conductivity should be checked while mixing the nutrient solution. While the electro conductivity reading will help determine the amount of dissolved nutrients, the pH reading will help in maintaining pH values at levels that will enable plants to absorb the nutrients.
Static solution culture involves growing the plants in water containers, which can vary in size from mason jars to giant industrial tanks. Air is usually introduced into the system to encourage the flow of nutrients from the solution to the plant roots. Nutrients are added to the solution based when needed.
Continuous-flow solution culture uses a mechanical component (a pump) to continuously move nutrient rich-solution past the plant roots. By keeping the solution in circulation at all times, it attempts to deliver the maximum amount of nutrients and oxygen to optimize plant growth.
“Substrates” refer to the solid (non-soil) materials in which the roots of the plants are suspended in medium culture aquaponics.
The most popular mediums are: